The app, released Thursday, allows users to catch up on their favorite shows in the hopes they'll return to TV when new episodes air. It also helps CBS earn advertising revenue, since mobile episodes will contain just as many commercials as regular TV. Ads on mobile devices can't be skipped like they can on a digital video recorder.

The launch brings CBS more in line with some other broadcasters that also stream recent shows on mobile devices for free. ABC and NBC offer apps that provide full episodes for free the day after airing, while Fox offers the same over apps if users prove they already pay for TV from certain providers.

Marc DeBevoise, general manager of entertainment, sports and news for CBS Interactive, said the apps represent a revenue-generating alternative to viewing on DVRs. DVR viewers often skip ads, and after a week, CBS no longer earns ad revenue from the recordings because that viewing isn't tracked a week after broadcast.

In contrast, app viewing can be measured and sold to advertisers regardless of how long after broadcast people watch them.

"As long as we can measure and monetize our content, we want to give it to them," he said.

The company said that later this year, it would introduce the app for other major mobile and tablet platforms, including Android and Windows 8.